The DEA receives information from confidential reports and letters, state licensing board determinations, and other state and federal agency actions. The DEA also engages in audits of medical ordering practices seeking discrepancies in the ordering patterns of certain drugs. The agency monitors reports of unusual patterns in patient deaths or other statistical anomalies.

There are several events that may prompt an investigation and possible action against the holder of a DEA registration:

The individual in question has falsified an application;

The registrant is charged with or convicted of a felony involving a controlled substance or a List I chemical (chemicals that have been identified as important to the manufacture of controlled substances);

The registrant has had a state license suspended, revoked, or denied;

The registrant has acted in such a manner that would make his or her registration with the DEA incompatible with public interest; or

The registrant has been excluded from participation in Medicaid or Medicare programs.

Frequently, the actions that bring one of these infractions to the attention of the DEA are through whistleblower reports or notifications from regulatory bodies. Mandatory reporting on drug losses pursuant to a DEA Form 106 may trigger an investigation into the individuals who had access to the controlled substances. Another factor that may trigger an investigation into all parties associated with a practice or dispensing organization is multiple overdose deaths for patients of that particular entity. Distributors of controlled substances also are required by law to report suspicious orders submitted by those practices and dispensing entities that they supply. As the DEA is taking swift and severe actions to enforce those laws and punish the offenders, more and more reporting is likely.

The DEA also monitors the use of the DEA registration number, which is intended to be used solely for the confirmation of DEA registration necessary for the dispensing of controlled substances. Use of this registration number in a manner inconsistent with historical or statistical use may cause the DEA to take a closer look at the activities of the registrant.